There is an urgent need for research on medication adherence in HIV-infected individuals that goes beyond ARV therapy and investigates determinants of adherence to medications for medical comorbidities. Due to the development of highly-effective antiretroviral (ARV) therapy, AIDS has been transformed from a fatal illness to a chronic one and mortality due to comorbid conditions has increased considerably among HIV-infected persons. As HIV-infected adults live longer lives, they are increasingly at risk for diseases of aging, including cardiovascular disease (CVD). HIV infection and ARV therapy have been associated with increased risks of CVD, and CVD now ranks as a major cause of death in this population. A major risk factor for CVD is hypertension (HTN), as well as stroke and renal failure (a common complication of HIV infection). Many patients do no achieve adequate disease control, despite the availability of effective medications for HIV and HTN. While medication adherence is a key aspect of chronic disease self-management, it has been well documented that approximately 50% of patients with chronic diseases do not adhere to their medication regimens, a pattern that translates into poor outcomes and increased medical costs. This study proposes to investigate adherence to antihypertensive medication in HIV-infected adults on ARVs with comorbid HTN, one of the most prevalent comorbid conditions in HIV-infected persons. Using Self- Regulation Theory as a framework, the focus will be on identifying potentially modifiable factors that could be the target of future nurse-led interventions to improve adherence, with specific attention for the role of race and ethnicity. The Specific Aims of this study are to: (1) Determine the relationship between disease-specific adherence factors (illness representation and beliefs about the necessity of medication and concerns about potential adverse effects) and adherence to antihypertensive and ARV medication in HIV-positive subjects with comorbid HTN;(2) Explore differences in HIV and HTN illness representation and medication beliefs among the three most prevalent racial/ethnic patient groups (blacks, Hispanics, non-Hispanic whites), controlling for stage of disease. The study will use electronic monitoring to prospectively assess adherence to one antihypertensive and one ARV medication over a 10-week period in an ethnically diverse sample of 200 inner- city HIV-positive subjects. This study will provide a model for integrating adherence to medications for comorbid medical conditions into nurse-led adherence interventions for HIV-infected persons. Study findings will serve as the basis for the development of research which will test the efficacy of a nurse-led adherence intervention targeting both adherence to ARVs and antihypertensives in HIV-infected persons with comorbid HTN. It will produce knowledge which can be used to effectively intervene to decrease the risk for cardiovascular disease among HIV-positive adults on highly-effective ARV therapy. PUBLIC HEALTH RELEVANCE: Hypertension is one of the most prevalent comorbid conditions in persons with HIV-infection and cardiovascular disease now ranks as a major cause of death in this population. This study will investigate determinants of adherence to the treatment of hypertension in HIV-infected persons with the goal of leading to interventions to decrease the risk for cardiovascular disease among HIV- positive adults on highly-effective ARV therapy.